Conventionally, oil has been applied to target objects such as workpieces and tools in order to improve machining accuracy and to extend tool life in machining. In a method of applying liquid oil directly toward target objects, an excessive amount of oil has been applied and it has taken time to remove extra oil, thus decreasing productivity. Furthermore, since the extra oil floats up around a coater, a countermeasure for preventing a working environment from getting worse has been necessary.
When applying oil in a drop-state, machining can be conducted with a very small (minimum necessary) amount of oil, thus not only improving machining accuracy and productivity, but also leading to the improvement of a working environment and the simplification of a plant. An example of coaters that can apply oil in a drop-state is proposed in Unexamined Japanese Utility Model Application Jikkai Hei 5-92596.
However, in an oil feeder mentioned above, it has been necessary to provide a casing for an oil dropping part, a passage for a high-speed gas, a Venturi nozzle and the like in a mist generating section. In addition, since an oil tank has been constructed individually, the configuration has been complicated.